Bread slicing machine having multiple reciprocating blades, with a guard



7 1948- H. THOMAS 2,436,703

BREAD SLICING MACHINE HAVING MULTIPLE RECIPROCATING BLADES WITH'A GUARD Filed Feb. 19, 1944 3 Sheets-Sheet l Fgb. 24, 1948.

H. THOMAS BREAD SLICING MACHINE HAVING MULTIPLE REGIPROCATING BLADES WITH A GUARD Filed Feb. 19, 1944 3 Sheets-Sheet 2 Feb. 24, 1948. H. THOMAS 2,435,703

BREAD SLICING MACHINE HAVING MULTIPLE RECIPROCATING BLADES WITH A GUARD Filed Feb. 19, 1944 3 Sheets-Sheet 3 Patented Feb. 24, 1948 BREAD SLICING MACHINE HAVING MUL- TIPLE RECIPROCATING BLADES, WITH A GUARD Henry Thomas, Chingford, England, assign'or to U. S. Slicing Machine Company, La Porte, Ind., a corporation of Indiana Application February 19, 1944, Serial No. 523,016 In Great Britain March 23, 1943 8 Claims. (Cl. 146-151) This invention relates to slicing machines in general, and particularly to machines for slicing bread. More specifically the invention relates to substance slicing machines wherein knife assemassemblies.

the machine.

sition.

2 knife and to clamp the substance during the cutting operation.

Another object is to provide a knife guard which may be operatively connected to a sup- Therefore, reference shall be blies reciprocate in opposite directions for sev- 5 port so that when the support is moved between ering the substance into a plurality of slices loading and slicing positions, the guard will be when the substance has passed through the knife moved from a knife-guarding position to a nonobstruotive position.

Machines of th type t t ordinarily have Numerous other objects and advantages will be no safety means to prevent damage or injury by pp throughout the p s of the f physical contact with the knife cutting edges ing Specification during the loading and unloading operations of The accompanyin drawings illustrate Certain Usuall the knive re mounted selected embodiments of the invention and the in a frame or housing which has an opening for views therein are as follows: the entrance of the substance, and in some inl s a d t l de e a nal Vie Of o e stances the machine may be provided with an form of slicing machine and embodying the opposite opening for the exit of the slices. As vention; the edges of the knives fa th ent a gpen- Fig. 2 is a. detail longitudinal sectional view of it is desirable that persons who operate the the machine Shown in 1 W t One of the machine should be prevented as far as prac- 2O cfi'mpohehts Shown in raised position; ticable, and o speci lly when performing the Fi 3 is a detail sectional view on the line 33 work of loading the machine with the substance of to be sliced, from having access through the 4 a detail Sectional View Similar to entrance to the zone where the knives are located. 2 but Showing a modified fOIm 0f knife guard; S the entrance opening usually will be masked Fig. 5 is an end elevational view of some of by the substance and/or its support sufliciently the mechanism shown in Fig. 4 parts being broto prevent the entry of a persons hand while n a for the sake of clearnessz the machine is actually cutting the substance, 6 is a detail longitudinal sectional View the present invention overcomes the inherent 0f another form of Slicing machine and ydisadvantages of conventional machines, s the invention;

The primary bj t of t present invention Fig. 7 is an elevational view of the machine is the provision of improved guard means for shown in 6, partsrbeing broken y for the the entrance opening of the machine during the Sake of 01951111838; and times the opening is unmasked by the substance 3 is a diagrammatic Schematic w Of or its support while the main components of the another form of slicing machine and embodying machine occupy the position in which the mathe inventionchine is loaded with the substance to be sliced. A machine of the kind to Which b ents A further object of the present invention is the of the Present invention are applied according to provision of a new and novel knife guard so posi- Figs- 1 o 3 a d igs. 4 nd 5 is shown and detioned that when slicing motion of the machine 40 scribed in United Stat/8S Letters Patent is stopped and the main components are posiissued April 6, 1943, a d s g ed to the tioned to receive the substance to be sliced, the p t assigne'eguard will be positioned t mask t knives, but made herein only to those parts of the machine when the slicing motion of the machine is started, with which parts according to the p esent inven the guard will be moved to a non-obstructive pohon are directly concerned- The machine shown in Figs. 1 and 2 includes Another object of the invention is the provision a supporting base or frame ID, a knife frame ll of a slicing machine which is provided with a ahdaloaf s pporting tray I 2, l3. novel guard arrangement t protect th user fr The knii e frame H is pivoted at M to the base injury by masking the knives during the machine loading position, there being releasable means in some instances to lock the guard in position to prevent accidental release of the guard.

A still further object is the provision of a knife guard to guard or mask the cutting edges of the and can be raised manually or by power from its lowered position shown in Fig. 1 to its raised position shown in Fig. 2. Springs (not shown) are provided to assist manual lifting of the frame. The knife frame I l is provided with two coplanar sets of knives l5, 16 which are spaced apart a.

. 3 slice-thickness, and these knives are simultaneously reciprocated in opposite directions to perform the cutting operation during descent of the frame.

The components I2, l3 of the loaf tray are both comb-like members, which are angularly disposed with respect to each other. The member I2 is secured to cranks ll, of which there is one at each side of the machine. These cranks are secured to a shaft |8 which is turnable by a handle |9 against the pull of a spring 20. The member |3, Fig. 4, is rigidly secured to a fixed anchorage bar 2|.

Means are also provided to hold the loaf L steady in the tray l2, l3 during the early portion of the slicing operation and until the knives have partly sliced the loaf; and in the construction illustrated by Figs. 1 to 3 the said holding means is made to function also as a knife guard according to the present invention.

The combined holding means and knife guard comprises another comb-like member 22 whose fingers are long enough to mask the lower opening of the frame I I, as Fig. 2 shows, which opening the loaf occupies in the slicing operation. The member 22 extends throughout the length of the loaf tray. At each end it has an arm 23, and these arms are pivotally mounted upon a shaft 24 which is journalled in brackets 25 on the knife frame. Links 26 are pivotally connected at 21 to the arms 23. Each of these links has a long slot 28, at the upper end of which there is an ofifset portion 29. Plates 30 are rigidly attached to the ends of the comb-like member I3. A pin 3| on each of these plates Operates in the adjacent slot 28. Each of the links 26 has a spring 32, the upper end of which engages the adjacent pin 3|. Each of the arms 23 has a lug 33 to engage the adjacent link 26 and another lug 34 is provided on each arm '23 to engage the knife-frame in order to support the comb-like member 22 in its lowest position (see Fig. 2). The slot 28, with its portion 29, and the pin 3| and spring 32 constitute a lost-motion device in the two-part linkage 23, 26 between the knife frame H and the anchorage plates 30 on the base I0, and the manner in which said device functions will be described hereinafter.

Means are provided to lock the comb-like member 22 against displacement so that it will exercise its function as a knife guard while the guard is in its knife-guarding position. The means acts also to release the guard whenever the knives are descending upon the loaf, at which stage the loaf L blocks the opening that leads through the bottom of the knife-frame to the knives. The guard-locking means comprise locking hooks 35, one at each side of the machine, each of said hooks being pivotally attached at 36 to the adjacent link 26 so as to enter into locking engagement with the respective pin 3|, which acts as a stationary stop. Each hook, Fig. 1, cooperates with another stop 31 on the base |0. Each hook has a spring-plunger 38, Fig. 3, which is engageable with the long slot 28 to hold the hook in the locking position. The spring-plunger 38 has a finger-knob 39 by which it can be withdrawn at will from engagement with the slot 28 in order to render the member 22 displaceable from its knife-guarding position.

In operation of the machine, assuming that the parts are in their out-of-use position shown in Fig. l, the knife frame I is raised (either by hand or power) until rollers 40 on the frame move clear of cams H on the base, at which point the cams 4| are pulled through links 42 by the springs 20 into the frame-supporting position, as shown in Fig. 2. The machine is now set to receive a loaf to be sliced, the knife frame H and the loaf support |2, |3 being fully separated. In this position of the knife frame, each linkage 23 is extended to the maximum angle permitted by the lugs 33, 34; the respective pin 3| occupies a place in the slot 28 spaced from the offset recess 29; and the respective locking hook 35 engages the pin 3|, being held in place by the springplunger 38 engaging the slot. When putting the loaf in the tray l2, l3, should the hand of the op-' erator come towards the knives l5, IS, the hand can not pass the knife-guard 22; and if the hand presses upward, the knife-guard will not give way, being locked for the time being by the locking hooks 35 against upward displacement.

Should the operator have to slice a loaf so large that it must enter the knife frame before the machine can be set to perform the slicing operation, the operator may withdraw each spring-plunger 38, whereupon each locking hook 35 may be displaced clear of the pin 3| to rest against its stop 31.

When the loaf is put on the tray |2, |3, the operator initiates the slicing operation by raising the hand lever I9, which action uptilts the comblike member l2 and pushes the cams 4| from below the rollers 40. The knife frame descends, and the knives are reciprocated. The links 26 begin to move under the pressure of the descending knife frame and the hooks 35 (assuming them not to be displaced by the operator from the locking position) leave the pins 3|. Therefore, the knife-guard 22 is free to rise under the upward pressure firstly of the loaf and latterly of the individual slices, until at a later stage in the descent of the knife frame the knife-guard swings beyond the slice tops into the Fig. 1 position. Thus, throughout the early part of the slicing operation the slices are held by the fingers of the knife-guard which therefore functions as a top clamp.

In the event that the operator has released the knife-guard to permit accommodation of an extra large loaf, the locking hooks 35 are automatically returned to the locking position in relation to the links 26 by the stops 31, under the constraint of which the spring-plungers 38 are forced again into engagement with the slots 28 as the knife frame descends into its lowermost position.

The construction shown in Figs. 4 and 5 has the knife-guard functioning solely as a guard and not also as a top clamp. Therefore, the guard does not require to be made to pass through the inter-knife spaces, but is made simply as a metal sheet 50 which masks the knives I5, I6 when the knife-frame H is raised for the loading of the tray |2, |3. The sheet 50 is arcuate, being supported at its ends by arms 5|, of which one is shown in the drawing. The arms 5| are each journaled on the adjacent plate 30, the boss of each arm 5| having a pinion 52 which meshes with a rack 53. The rack 53 is pivotally connected at one end to the adjacent end of the comb-like tray member l2 and is guided at the other end through a sleeve on the casing 54 of the pinion. The arrangement is such that the position of the guard 50 is determined by the position of the tray member l2. When the member |2 is lowered on completion of the ascent of the knife-fram H, the guard is swung upwards into its guarding position. When the tray memher i2 is uptilted by the operators action of start ing the machine following each tray-loading operation, the guard is swung downwardly into a non-obstructive position, as shown in dot-dash lines in Fig. 4.

The invention illustrated in Figs. 6 and 7 is applied to a slicing machine having a stationary housing 60 in which one or two sets of knives 6| reciprocate in a vertical plane. The knives are spaced apart to the extent of a slice thickness. The substance support consists of a channel-section tray 62 and a pusher 63. The tray 62 is horizontal and leads through the housing by way of an entrance opening 60A therein. The tray continues through a similar exit opening (not shown) at the opposite side of the housing and functions there as a slice receiver. The pusher 63 is formed with forwardly projecting fingers 64 adapted to pass into the inter-knife spaces during the slicing action. The pusher 63 is pivotally attached to an assembly 65 provided with a hand grip GB and with a guide bearing 61 which is slidable on a horizontal guide bar 68 secured within the machine base 69.

A machine of the kind shown in Figs. 6 and 7 has the pusher withdrawn fully from the housing, and when a loaf L is placed in front of the pusher upon the tray 62, the pusher is advanced by the operator sufliciently to force the loaf firstly, and the slices thereafter, through the housing to the slice receiver at the opposite side. Thereafter the pusher is withdrawn in readiness for another loading operation.

The machine is equipped with a k-ife-guard which closes the entrance 60A so long as the pusher 63 is withdrawn from the housing, Figs. 6 and 7. The guard consists of a plate TU which is pivoted on top, at H, to the housing. The plate 12 extends across the width of the tray 62 and is formed throughout its length with fingers 12 adapted to enter the inter-knife spaces. A few of the fingers 12 are shown in Fig. 7. In the passage of a loaf through the housing, the loaf engages the guard plate 10 and pushes it out of the way. However, the fingers 12 continue to rest upon the slices in their passage between the knives and therefore act then as a top clamp. When the loaf has completely passed through the housing, the plate 10 drops by its weight against the pusher teeth 64 and on withdrawal of the pusher eventually adopts the pendulous position in which it is shown in Fig. 6.

. The knife-guard, Figs. 6 and 7, is provided with a locking device which serves to prevent displacement of the guard from the opening 60A; for example, by the operator when loading the tray 62. The locking device comprises a lever arm 13 which has a roller 14 that co-operates with an arm 15 on the guard-plate 10. The lever 73 is secured to a fulcrum-shaft 16 which has arms 77, '18 respectively at opposite sides of the housing. To the arms TI, 18 there are secured the ends of a light flexible cable '19. This cable extends downwardly from the locking device to two guide rollers 80 at opposite sides of the base, then horizontally to the end of the base 69 beyond the furthermost limit of the pusher plates withdrawal, and finally across said end, the cable being guided there by rollers 90. The cable extends through opposite ends of a double arm 9| forming a part of the guided pusher assembly 65. Each end of the double arm 9| is fitted with a gripper 92 through which the cable 13 passes. Each gripper 92 is normally open under spring pressure. The assembly 65 is provided with two pivotally mounted arms 93'which are pressed up-" wardly by springs 94 towards adjustable limit stops 95. When either arm 93 is depressed it engages the respective gripper 92 and forces that gripper to clamp the cable 19. The arms 93 co-operate with mechanical switch devices at opposite sides of the base 69. One of these devices consists of a cam 96A and a pawl 91A, Fig. 6, which is normally uptilted under spring pressure but which can be depressed. The other switch device comprises a cam 96B and a pawl 9'53, being similar to the switch device already described but, as Fig. 6, shows, being directed oppositely and being set more closely to the housing 83. These switch devices co-operate with rollers 56 provided at the ends of the arms 93.

Assuming that the pusher 63 is fully withdrawn and the tray 62 is loaded with a loaf L, as shown in Fig. 6, the locking arm I3 depends almost vertically and engages the arm 15, so that the guard plate til can not be displaced. When the operator advances the pusher 63, the roller 98 at one side of the machine engages the cam 91A and is depressed thereby, being held depressed throughout thepassage of the roller under the cam 535. During such passage the gripper 92 at that side of the machine is' forced by the adjacent arm 93 to clamp the cable 19, with the result that the locking arm 13 is swung (clockwise as seen in-Fig. 6) away from the arm '15. Accordingly, the advancing loaf L on contacting the guard-plate l0 pushes it out of the way, and the slicing operation proceeds without obstruction from the locking device. On the return of the pusher by the operator, a point is reached at which the pusher leaves the entrance 60A. At that point the plate it) hangs vertically but is unlocked. Then the pawl 91B is engaged by the roller 98 at that side of the machine. The roller is depressed by the pawl and remains depressed throughout its passage under the cam 86B. During such passage of the roller, the gripper 92 at that side of the machine clamps the cable 19 with the result that the locking arm 13 is returned to its locking position in engagement with the arm 25. The guard remains locked in this manner until the next forward movement of the pusher. It has been described how each roller 98 is acted upon by the respective switch device in one direction of that rollers motion. Each roller 98 rides idly on top of the respective cam 96A or 9613 during the return motion and depresses the pawl 97A or 978 out of its Way. Each switch device, therefore, exercises only a one-way action onthe co-operating roller 98.

The locking arm 13 may be provided with stops to limit its movement in both directions, and the roller 98 may be made of resilient material to ailow slip of the cable when the arm is against a stop.

The slicing machine shown diagrammatically in Fig. 8 illustrates the invention applied to a slicing machine having a stationary housing 60.

One or two sets of knives 6| reciprocate in the to opposite ends of the pusher. Each link-and lever mechanism comprises a link I03, a lever I04 which is fulerumed at HISto the base I06 and e op.of-whichiissicklezshapedi andcanarm? I n nxt pusher, ,this.arm=-b.e ns piyotally connected to the sickle shapedtop. Thereis-a complete link and-lever. mechanism, at: each. side of; the;- slicing machine baseiflfi, 'I'heDi15herG3 i$aP, .V-- otally attachedto; aslide-block I 081 which: iS-zSlidr able in achannel guide Ill9;.on-,top of;which-,thetray 62. is provided. Thetrayxdl leadstmaslicereceiver I II! at the. opposite-sidegofithegcasing'fifl; In operation of, the machineyassuming that the pusher 63 .is fully withdrawn; .thertrayqiiais lo ded: and the hand-lever I410 israisedz. Thepusher-ii. therefore is .advanced .touforce the loafiL throu h the housing to .beslicedtnereflm thesllcespassin from the housing to' -the: slice;rr.eceiver I10.

The machine, Fig 8; is-eQuipped with a. knife. guard III which extendsacrossrrthe entrance side of the housing'and is: supported .at veacheend. by. a: plate H2 pivotallysupportediat I I3;-on the-adiae cent side of the housing. One-of: the-plates L12- has an arm I I4-.whi.ch co-operates with-a locking, device. This device comprises; the overturned head I I6..of.a sliderod Hi1 suppo t d in bearings I I8. on the adjacent-.side ot'the housing-50. The foot of the rod I IJ-consistsofsa projection I.I9' adapted to enter a channel cam-.121). formed in the sickle-shapedtopof. the-lever IN; The rod II II hasza, stop I 2.,I which limits-upward movement of. the rod under the pressure oil-a sprin I 22.

The guard-supporting plate- Id2 at each-side of the. machine, Fig; 8, aISO,Sl.1pDlts.the-ends0f a curved plate. I23 constituting. a? top :clamp. The plate I23. is pivotally attaohedgtoseachasupporting plate H2. and is.pressed-: therefrom-. by a spring I 24. The guard lilzLandthetopiplate I23 would be formedwith fingers insofaras. necessary, for entry into the inter knife spaces.

The guard, its locking device and :the topolam-p, asshownin Fig. 8, operate asiollowsz 'Whenthe hand lever I00; is raised to-.advance the pusher 63', the leverin is.swu'ng.to-,the right (as-viewed inEig. 8) into the position-in whichitis shownin dot-dash lines. Accordingly, the=rod.| Iilziscausedto slide upwardly in itsbearings untllcthe stop I 21 .reaches the uppenbea-ring .I I Brat-which stage the cam I2.0':passes.f-rom-the projection H9. in this motion ofsthe red-I11; the-.locking-restraintis. withdrawn from the guarda-supportingplates -I.I2 withthe result. that theentirestructure I I I, H2 and. I23 swings about. the pivots.li8, thefingers of guard. III passing between the knivesout: of: the way of the. oncoming loaf-7L- The=spring-. loaded top clamp .I 23 :howevepmoves into the path of the top of the loaf with the result that iticlamps.

the top of the slices..-as-.they.-pa.ss betweentheknives.

The pusher. 6.3, Fig. 8, is returned zby=-depresslng the'hand lever I00, Bythisraction; the-cam-JZII' returns into engagementwithztheprojection H9 and lowers the rod III into the position in whichit positively. holds theguardaHLin theiguarding position.

Changesmay be made lathe form, construction and arrangement oi-the-parts without departing from the-spirit of thein-ventionor sacrificing any of its advantages,- and-theright is hereby reserved to make all such c-hangesas-fairly fall'within the scope of thefollowingclaims.

The invention is hereby claimed as follows;

1-. A- slicing machine comprising a knife-frame, inwhich a number of knives are-reclprocably arrangedandare spaced aslice-thlckness apart,- a base in relation to whichthek-niie-frame-eanbe raised to provideasubstance-recelvingspace between it and the base, a substance-supportmounted on the base and; formed; comb-1ike;wlth-,

substance -engaging fingers adapted to pass; through: the, inter-knife spaces, a: knife-guard;

supported by the knife-frame and extending below the knives when the knife-frame isuptilted a locking member acting toprevent withdrawal of said guard, and an operative connection be-.-- tween the said guard andthe base serving to unlock said guard when said frame descends to pe11- form a slicing stroke.

2.; A slicing machine as claimed. in claim 1 wherein the knife-frame and the base are interconnected by a two-part linkage, one part of. which carries the knife-guard and the other part.

. of: which carries the locking member, and. where+- in said memberis engageable with astationary stop.

3.. A slicing machine as claimed in claim 1 wherein means, are provided for rendering the;

. locking member inactive at will when in its op-- erative setting, said means being displaceable into ainon-locking position to permit. withdrawal of theknife-guard.

4. A slicing machine as claimed-in claim 1 in which the knife-guard. embodiesv a. comb-like portion. disposed. to engageand clamp the sub-.

stance before and after being sliced.

5 A slicing machine comprising a; housing, a. number of knives reciprocably arranged in the housing. and spaced a slice thickness apart, a; substance-supporting tray leading to .an-entrancein the housing, a pusher for pushing the sub= stance through the entrance for; slicing in the. housing by the knives, a knife guard at the entrance, means moving said guard between a guarding position between the-pusher and theknives and a non-obstructiveposition, a locking. device to prevent displacement of the guard from; the guarding position while the pusher is with-. drawnfrom the entrance, and means whereby.-

the said locking device will be responsive in its.

operation to the operation of. said pusher.

6.. A bread slicer comprising a housing having an opening, a plurality of cutting knives arranged in the housing across the opening. and- 1! dental contact with the knives prior. tothe slicing operation, said guard member comprising-a,- plurality of fingers. adapted to. pass into the spaces between the knives, an arm on said guard member, a pivotally mounted locking member to lock-ingly maintain theguardmember in locked position, a pusher to push a loaf through the knives, andmeans controlled by the positionof the=pusher to operate the locking member to either locked or unlocked position.

7'; A- slicing machine embodying a. housing, a-

number of. knivesreciprocably. arranged in thehousing andspaced a slice thickness apart, a.

drawn from-the entrance, and means'connectlngthe locking device to the pusher, for displacementthereby to lockandunlock-the knife guard, by.- meansof devicesone of which is actuated early.

in the advance of the pusher and the other of which is actuated when the pusher is being withdrawn from the housing.

8. A slicing machine embodying a housing, a number of knives reciprocably arranged in the housing and spaced a slice thickness apart, a substance supporting tray leading to an entrance in the housing, a pusher for pushing the sub stance through the entrance for slicing in the housing by the knives, a. knife guard at the entrance, means moving said guard between a guardingposltion between the pusher and the knives and a non-obstructive position. a locking device to prevent displacement of the guard from the guarding position while the pusher is withdrawn from the entrance, and means connecting the locking mechanism with the pusher, said connecting means operating that when actuated to advance the pusher the locking device will be rendered inactive.

HENRY THOMAS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS m Number Name Date 252,269 Sill Jan. 10, 1882 2,147,322 Tuthill et a] Feb. 14, 1939 2,280,059 Brustowsky Apr. 21, 1942 2,315,767 Brustowsky Apr. 6, 1943 FOREIGN PATENTS Number Country Date 125,775 Austria Dec. 10, 1931 

